366 Arrangement of Minerals. 



Genu3 X. Platina. 

 Tessular. Uncleavable. Colour steel-grey. Ductile. Hard- 

 ness 4.0 — 4.5. Sp. gr. = 16.0 — 20.0. 



Genus XI. Iron. 



Tessular. Colour pale steel-grey. Hardness = 4.5. Sp. gr. = 7.4 

 — 7.8. 



1. Octahedral Iron. 



Genus XII, Coppeb. 

 Tessular. Colour copper-red. Hardness = 2.5 — 3.0. Sp. gr. 

 = 8.4 — 8.9. 



1. Octahedral Copper. 



Order HI. PYRITES. 



Metallic. Not lead-grey, not black. Streak black. Hard- 

 ness = 3.0 ^ 6.5. Sp. gr. =z 4.1 — 7.7. 



Genus I. Nickel-Pyrites, or Copper-Nickel. Arsenical 

 Nickel. 

 f Prismatic. Colour copper-red. Hardness = 5.0 — 5.5. Sp. gr. 

 = 7.5 — 7.7. 



1. Prismatic Nickel-Pyrites. 



Genus II. Arsenical Pyrites. 

 Prismatic. Colour not inclining to red. Hardness =: 5.0 — 6.0. 

 Sp.gr. =5.7 — 7.4. 



1. Axotomous Arsenical Vyntes {^Fer Arsenical, "E..^ 2. Prismatic 

 Arsenical Pyrites {Fer Arsenical, H.) . 



Genus III. Cobalt-Pyrites. 



Tessular. Colour white, inclining to steel grey or red ; steel-grey. 

 Hardness = 5.0 — 5.5. Sp. gr. = 6.1 — 6.Q. 



1. Octahedral, or Tin-White Cobalt-Pyrites {Cobalt Arsenical, H.) 

 2. Hexahcdrab or Silver-White Cobalt Pyrites {Cobalt gr is, H.) 

 S. Isometric Cobalt Pyrites {Kobaltkies), 4. Eutomous Cobalt- 

 Pyrites {Nickelspies-glaserz, Hausmann). 



Genus IV. Iron-Pyrites. 



Tessular. Rbombohedral. Prisniatic. Colour yellow, sometimes in- 

 clining to copper-red. Hardness = 3.5 — 6.5. Sp. gr. = 4.4 — 5.05. 

 1. Hexahedral Iron-Pyrites. 2. Prismaticlron- Pyrites. 3. Rhom- 

 bohedral or Magnetic-Iron-Pyritcs, 



